JPH02154296A - Video image scrolling system - Google Patents

Abstract

PURPOSE:To easily scroll an image by generating a SYNC signal and an out-of- phase dummy SYNC signal, and using the dummy SYNC signal as a reset signal and resetting an address counter when a display on a monitor is scrolled. CONSTITUTION:A display circuit 1 is equipped with the address counter 2, a memory 3, the monitor 4, and a changeover switch 5. Further, the SYNC signal and dummy SYNC signal are generated. The monitor 4 displays data read out of the memory 3 as video information in synchronism with the SYNC signal. The changeover switch 5 is an electric switch to select the SYNC signal when the display is not scrolled or the dummy SYNC signal when the display is scrolled. Thus, the address counter 2 is reset with the dummy SYNC signal as the reset signal, so the image is easily scrolled.

Description

[Detailed description of the invention] [Industrial application field] The present invention relates to a video information scrolling method.

[Prior Art] When writing video information to a memory as digital data and displaying the data read from the memory on a monitor in synchronization with a SYNC signal, the first method for scrolling the video information is to There is a method to rewrite continuously.

That is, as shown in FIG. 4 (1), the memory address "
0''~r 239J contains data such as character code A0
~A23, B0~B113, ~J0~J13 are stored. This data A0~A2a, B0~'Baa,
, J0 to Jt3 are scrolled upward by one line on a 24x10 pixel monitor, all data Bo=B2s, to Jo-Jzs are stored at memory addresses rOJ to r239J, as shown in FIG. 4(2). , K, - is rewritten as 2 and displayed on the monitor. After that, all data is rewritten in the same way. The same applies when scrolling in the horizontal direction.

A second method is to reversely change the read address of the memory. As shown in FIG. 5, this second system includes a monitor 51, a memory 52, an address counter 53 with preset, a memory 54 for preset data, and an S\NC counter 55. In addition, the scroll control signal and SYN which determine the amount of scrolling are
The C signal is converted to quasi-6iii.

SYNC counter 55 outputs a SYNC signal. The preset data memory 54 outputs a preset signal in response to the scroll control signal. The preset address counter 53 is reset in response to the SYNC signal, and starts counting from the preset value in response to the preset signal.

In this second method, address "O" of memory 52
~l" 239j, as shown in FIG. 6 (1), data A such as character code. -A23, B, -B
23, to J o'= 123 are stored. This data A. -A23, B0~B23,~J0~J2'
When scrolling 1 character line upward on the 24×10 pixel monitor 51, as shown in FIG. 23, change the initial value of the count value of the preset address counter 53, and set the address "2" to
4" and access data B. -B23, ~J0~J
23, to K0~! 3 is displayed on the monitor 51. Thereafter, the data is similarly rewritten line by line and accessed by increasing the address by +24.

[Problems to be Solved by the Invention] However, in the first method, in order to scroll, it is necessary to rewrite a large amount of data in a short time.

In the second method, an address counter with a preset was required for scrolling, and the initial value of the count had to be changed in a complicated manner.

An object of the present invention is to solve the above-mentioned technical problems and provide a video information scrolling method that allows easy scrolling.

[Means for Solving the Problems] The video information scrolling method according to the present invention includes an address counter that is reset by a reset signal, video information written as digital data, and data written according to the count value of the address counter. It is equipped with a memory to read out, prepares a SYNC signal and a false SYNC signal that is shifted from the SYNC signal, and when displaying the data read out from the memory as video information on the monitor in synchronization with the SYNC signal, the display on the monitor is When not scrolling, the address counter is reset using the SYNC signal as a reset signal, and when the monitor display is scrolled, the address counter is reset using the false SYNC signal as the reset signal. .

[Function] When displaying the data read from the memory as video information on the monitor in synchronization with the SYNC signal, when scrolling the monitor display, the address counter is reset using the false SYNC signal as a reset signal. You can easily scroll through the video.

[Example] Hereinafter, the present invention will be described in detail based on the drawings.

FIG. 1 is a simplified circuit diagram for achieving a video information scrolling method according to an embodiment of the present invention.

This display circuit 1 includes an address counter 2, a memory 3, a monitor 4, and a changeover switch 5. Also, S.Y.
An NC signal and a false SYNC signal are prepared.

Address counter 2 is reset to "0" by a reset signal. Memory 3 is where video information is written,
The written data is read out according to the count value of the address counter 2. The monitor 4 displays the data read from the memory 3 as video information in synchronization with the SYNC signal. The changeover switch 5 is an electric switch, and selects the SYNC signal when not scrolling, and selects the false SYNC signal when scrolling. Depending on this selection, a SYNC signal or a false SYNC signal is applied to the address counter 2 as a reset signal.

The SYNC signal includes an H3YNC signal and a VSYNC signal. The false SYNC signal is offset from the SYNC signal and includes a false HSYNC signal and a false VSYNC signal. That is, the false H8YNC signal is out of alignment with the HSYNC signal,
The false VSYNC signal is out of sync with the VSYNC signal.

Next, a case in which video information is scrolled will be explained. Addresses “0” to r 239J of memory 3 contain the information shown in Figure 2 (
As shown in 1), data A such as a character code. −
A2B, B0-Bts,... J0-J23 are stored. Here, for convenience, it is assumed that the data in the memory 3 is scrolled upward line by line without being rewritten. In this case, as shown in Figure 2 (1), the false VSYNC
Shift the signal one line from the VSYNC signal. Also, for convenience, if you do not scroll, address counter 2 will be set to "0".
Suppose that the address counter 2 is reset when counting from ``0'' to ``9'', and when scrolling, the address counter 2 is reset when counting from ``0'' to ``8'' due to the false VSYNC signal. On the other hand, monitor 4 has VSYN
Display is performed based on the C signal. Therefore, the monitor 4 reads "0" of the address counter 2, as shown in FIG. 2 (2).
～Address “0” of memory 3 by counting “8”
~r215J data is displayed, and address r216J~ of memory 3 is displayed by counting 0 of address counter 2.
Data A from address rOJ to "23" in place of r239J. ~Display A2s.

In the next display, the address counter 2 is shown in FIG.
As shown in 3), it is counted from "1", and "8"
” to reset. That is, the false VSYNC signal is shifted by one row. Therefore, the monitor 4 is
), “1” to “8” of address counter 2
The display starts from the data at address "24" in memory 3 by counting, and data B at address r191J is displayed.
0~Bts, ~I0~its are displayed, and the address “O” and “1” of address counter 2 are displayed.
0” to “47” data A0 to A23, B0 to 13it
Display.

In this way, scrolling of the video information is performed.

Note that when displaying new video information from the bottom of the monitor 4, the address rOJ for the youngest line of the memory 3 ~ "2
3" and then rewrite the data 0 to 23, . . . one line at a time.

Furthermore, if the false VSYNC signal is shifted from the VSYNC signal one line at a time, it is possible to scroll one line at a time even when text characters are displayed. Furthermore, even when one dot is displayed on multiple lines, it is possible to scroll one line at a time. Furthermore, by adjusting the deviation of the false VSYNC signal from the VSYNC signal, it is possible to scroll by one line or one line in several frames, scroll downwards, or scroll diagonally.

Further, depending on the deviation of the false H3YNC signal from the H9YNC signal, scrolling can be performed in the horizontal, left-right, and diagonal directions.

Creating such a false SYNC signal is easy and can be easily prepared. Therefore, the video information can be easily scrolled. Further, there is no need to make any special arrangements for the address counter 2, and it is sufficient to count as usual.

In addition, as another embodiment of the present invention, as shown in FIG. 3, a counter 6, a memory 7, and a digital comparator 8 may be used in place of the false SYNC signal and changeover switch 5 in FIG. . A counter 6 measures the display position of the scanning line.

The memory 7 is for setting the scroll amount.

The digital comparator 8 compares the scanning position of the counter 6 with the scroll amount setting value of the memory 7, and when they match, the digital comparator 8 automatically outputs SYNC when no scrolling is performed.
When the signal is scrolled, a false SYNC signal is output to the address counter 2 if the signal matches the set value.

Therefore, the display circuit 9 can also easily scroll the video information. Further, there is no need to make any special arrangements for the address counter 2, and it is sufficient to count normally.

[Effects of the Invention] As described above, according to the present invention, when displaying data read from a memory as video information on a monitor in synchronization with a SYNC signal, when scrolling the display on the monitor, false SYNC Since the address counter is reset using the signal as a reset signal, the video can be easily scrolled.

[Brief explanation of the drawing]

FIG. 1 is a simplified circuit diagram for achieving a video information scrolling method according to an embodiment of the present invention, FIG. 2 is a diagram for explaining the case where video information is scrolled, and FIG. A simplified circuit diagram for achieving the video information scrolling method of the embodiment, FIG. 4 is a diagram for explaining the first conventional video information scrolling method, and FIG. 5 is a simplified circuit diagram for achieving the conventional video information scrolling method. The converted circuit diagram, FIG. 6, is a diagram for explaining the case where the video information in FIG. 5 is scrolled. 2... Address counter 3.7... Memory 4... Monitor 5... Selector switch 6... Counter 8... Digital comparator! Wari F False VSYNCVSYNC (Engineering number 1 QVSYNCVSYNC 1E No. 1 '% Figure Figure ■

Claims (1)

[Claims] An address counter that is reset by a reset signal, and a memory in which video information is written as digital data and the written data is read out according to the count value of the address counter, and a SYNC signal and a SYNC signal. Prepare a shifted false SYNC signal, and when displaying the data read from memory as video information on the monitor in synchronization with the SYNC signal, if the monitor display does not scroll, use the SYNC signal as a reset signal to address the A video information scrolling method characterized in that when a counter is reset and a display on a monitor is scrolled, an address counter is reset using a false SYNC signal as a reset signal.